Arc welding



Oct. 26. 1926. 1,604,180

J. F. LINCOLN ARC WELDING Filed April 4. 1921 I Z 7- za- 19 i i 2 f9.

+ WELDING; (JRQU T 2a 1 b v V 21: i 1 1' 4 1 INVENTOR.

Jim as fi'izzcaizz BY v Patented Oct. 2 1926. J

UNITED STATES PATENT OFFICE.

JAMES F. LINCOLN, OF CLEVELAND, OHIO, ASSIGNOB TO THE LINCOLN ELECTRIC COM- PANY OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

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Application filed April 4,

which the necessary heat is developed by the diagrammatic modifications.

' 'ti'ated are disposed with their edges which are to be resistance-of the joint to the passage of current. thereacross, have been devised, but without proving wholly successful under the conditions stated. The object of the present invention accordingly is the provisionof an arc welding process and apparatus for use 'thereinwhereby a continuous butt weld may be formed between the meeting edges of sheets of relatively light'gauge, although of course such process and apparatus are not necessarily limited to working ,with such light gauge materials.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the steps and means hereinafter fully desoribed,'the' annexed drawing and the following description settin forth in detail certain means and one mo e of carrying out the invention. Such disclosed means and mode illustrate, however, but several of various-ways in which theprinciple of the invention may be used, it being noted that only the apparatus aspect of the invention is claimed herein,-the process involved forming the subject matter of a'separat'e divi- 0 electrode (see Fig. 3), it is rendered impossional application, Serial No. 620,746)

In said annexed drawing Fig. 1 is a perspective view more or less in character, illustrating my improved method of welding; Fig. 2 is a cross-sectional detail; Fig; 2 is a.- similar view showing the resultant joint; Fig, 3 s a' side view of a typical apparatus; Fig. 4 we diagram of the motor circuits involved .m such apparatus; and Figs. 5, detail views similar to Fig. 2,

(filed February 23, 1923,

but showing The distinguishing features of my present improved process are perhaps. best illusin Fig. 1, wherein the two sheets 1-1 abutting joined together in substantially is left relation. Suflicient space, however,

6'and 7 are.

may be v \I 1921. 7 Serial No. 458,263.

The sheets 1 with strip 2 thus interposed between their edges are preferably supported on a plate 3 of copper or other .heat conducting material, and in order to increase the cooling eifect of the plate the latter may be made hollow. as indicated, with suitable connections for circulating water through its interior. I

The welding, as previously indicated, is

. accomplished-by means of an electric arc, a.- carbon electrode 4 being employed, and the welding circuit including such carbon and either the late 3 and strip 2 or such strip alone. It asbeen found that, .due to the small amount of contact which the strip has with-the plate, where the return circuit is through the latter, the circuit will be more or' less diverted through the sheets 1 which have a much larger areaof contact with the plate and thus the fusion of the strip will e retarded. I However, by returning the current directly through the strip, as by means of a brush 5 moving in unison with the sible for the arc to be diverted to either of the sheets and it is caused to play directly on the strip. The latter is thus quickly 'melted down as the carbon pencil is drawn along it and the adjacent edges of the sheet 1 interfused, forming a close and homogeneous joint that is smooth and continuous on both sides of the sheets.

The movement of the electrode, both Ion-1 gitudinally of the strip 2 and toward same, in order to varythe character of the arc,

anism, more or less automatic in character. Thus the control of the rate of feed of the carbon along thestrip or seam may be made todepend on the current flow oramperage .throu h the arc, while the vertical feed of the rode, i. a, its movement towirds effected by means of suitable 1116.611",

the strip or seam, m ay be controlled by the The electrode 4, as well as the brush 5, which is here shown as forming the connection for the return circuit direct with strip 2, both depend from .a suitable slide or carriage 6 that is mounted so as to be movable lon- 'tudinally of the work in line with the seam;

1 ior the purpose of thus feeding the slide 6 a screw .7 is provided, the same being rotated by a motor 8 that has adjustable fieldswith thearmature circuit across a resistance in series with the arc, the fields being thus adjustable or variable so that the speed canbe changed. For gradually lowering the electrode 4 the stem 10 of the the support for such electrode is vertically movable in slide 6, its movement being controlled by a nut 11 or equivalent device operated by a motor 12. A spring 13, in conjunction with the shoe 5 serves to hold the latter in contact with the strip 2, irrespective of the vertical position occupied by the e1ectrode-support. The motor 12, whichis thus arranged to feed the electrode is of special construction, one

field getting its eliciting current as a shunt across the are, the other field being excited from a constant source of voltage from some outside source, which can either be-current from the exciter on the welder, or else current fromsome external direct current source. The two fields, under normal conditions, will be equal and so no movement/of the armature will occur with the current flowing through it; however, if the are becomes too long, the field excited across the arc will become stronger than the othenfield and the armature will turn in one direction, feeding the armature down. Conversely, when the arc became too short, the other field will become stronger than the field across the arc and will cause the .armature to revolve in the opposite direction until l the are is of the proper length. In this I way the voltage across the are will be maintained constantat'all times.

From the,- foregoing arrangement of a paratus' it will be seen that not only is the electrode advanced longitudinally of the stri at a -greater or lower rate ofspeed, de-

we n, up we;

pen upon the volume of the current flow, as determined by the, adjustment of resistance 9{ but the lowering of the electrode v n s end othe'1atter burns away, due to the change "in -volt-,

are.

' st-rip automatically occurs as I a strip such as m s e g he sh to be welded, such. edges may be bronghtdirectlymto contact as shown in Fig. 5, and. a strip corresponding with said Such strip in this case may be circular in cross section as shown, or rectangular, as

in the case of strip 2, and the latter may ing u a portion of one of the sheets along the edge in question; or, as shown in Fig. 7, the edges of.both sheets maybe thus turnedu. I j

The mode of operation and form of ap aratusused, where the stripis formed an disposed as in these last mentioned figures, will remain the same as that previously described in connection with the arrangement wherein the strip is separate from, but clamped between the' juxtaposed edges of the sheets.

It will be understood that while reference has hereinbefore been made to sheets 1 as [though they were entirely independent of may be formed as shown in Fig, 6 by turn-- teach other, they may consists singly or the I opposite portions of a single around into circular form so as to be brought into juxtaposition, in the-fashion eet bent desired; The term sheets-- is accordingly to be interpreted as including either two wholly independent sheets, or parts of a sheet thus bent around andbrought into substantially the same plane. The material of the sheets will, of necessity, be metal, such as iron or steel, capable of being worked electrically in the fashion described, and the strip,'where separate from such sheets, may

between the twosheets or laid on top of the v joint, of such special alloy steel a weld of superior character may be secured. For example, if a filler rod of Harvegized armor I- will plate steel is used a. very tou w 'chwill result, the tensile. strength 0 exceed 100,000 pounds per square inch, while its ductility and toughnesswill be much greater than with the usual mild steel. By using fillerrods of other alloys the charac, ter of thew'elding joint can be varied to suit special requirements.- It will also be I understood that the sheets'as well as the be held tron.

em oyed, produces-a jointor eweld that wi bend much. further without breaking,

and is-otherwise superion This is. due.

in place by means of suitable clamps (not shown),-.pending the welding opera-f- My-mpma me, a anataiaaa j tion thatin which a metallic electrode 'is the with .the metallic electrode:-.-

by ima V I the work, an electric circuit including 7 provided the means siderable amount are accordingly set up in the weld; whereas with the carbon electrode method, as hereinbefore described, the whole weld is heated to the same temperature and cooled at the same time, so that no such shrinkage stresses are set up.

Other forms may be employed embodying I the features of my invention instead of the "'"onehere explained change being made as 10 regards the. mechanism herein disclosed, stated by any of the following claims or the equivalent of such stated means be employed.

WI therefore particularly point out and dis tinctly claim as my invention r V 1. In apparatus of the character (lescribed,-the combination of a support for "the articles to be welded together, an electrode, means for traversing the latter longitudinally of'the seam between such articles, anelectric 'circuit'including such electrode and the work, and anelectric motor adapt ed to drive such-traversing-means,said motor having adjustable fields with the armature circuit across a' resistance in series with the are formed between said electrode and the work.

2. In apparatus of the character described, the combination of a support for the; articles to be welded together, an electrode, means for feeding the latter towards electrode and the work, and an electricmotor adapted to drive such feeding means,

said motor having one magnet field connected in shunt across the are between said said electrode and work, and another field excited from a constant potential source. 3. In apparatus of the character. described, the combination of a support for the articles to be welded together, an electrode, means for feeding the latter towards the work, an electric circuit including said electrode and the work, a variable resistance also included in said circuit, an electric moitor adapted to drive such feeding means,

said motor having one magnet field con,-

nected in shunt across the are between said electrode and work, and another field excited from a constant potential source, means for traversing said electrode longitudinally ot' the seam between such articles, and an electric motor adapted to drive such traversing means, said motor having adjustable fields with the armature circuit across a resistance in serles with, the arc formed'between said electrode and the work.

I 4: In apparatus of the character dey between said-electrode and the work.

this 31 day of March, 1921.'

Signed by me,

' JAMES F. LINCOLN. 

